In recent years, a microscale analysis channel or the like is formed on a small substrate made from, for example, silicon, silicone, or glass, by a semiconductor fine processing technology to configure a microchip having the small substrate and the microchannel on the substrate. A microreactor having such microchip and used to isolate, synthesize, extract and analyze a trace amount of sample drug (test drug) is drawing attention.
A reaction analysis system that uses the microreactor is referred to as “micro total analysis system” or “μTAS.” When the μTAS is used, a ratio of a surface area of a test drug (sample drug) to a volume becomes large. Thus, a reaction analysis can be carried out at a high speed and high accuracy. It is also possible to make a compact and automated system.
The microchip has a fluid passage (flow path) 10, which is referred to as a microchannel, provided in the microchip. A test drug is disposed in a reaction area of the microchannel. The microchip also has other areas having various functions, in which fluid control elements and components (e.g., micropumps, microvalves, micromixers, filters and sensors) are provided. These areas are integrated in the microchip such that the microchip can be used in various applications.
Typically, the microchip includes a pair of microchip substrates bonded to each other, and a fine channel (microchannel) formed on the surface of at least one of the two microchip substrates. The fine channel is, for example, 10 to several hundred micrometers in width and 10 to several hundred micrometers in depth.
The microchip is typically used in analysis in the fields of chemistry, biochemistry, pharmacology, medical science, and veterinary science, including gene analysis, a clinical diagnosis and a drug screening. The microchip is also often used when synthesizing chemical substances, or measuring environmental data.
For example, when the microchip is used in medicines or medical devices, the microchip is included in (or used as) a preserving container to preserve a living-thing-derived substance (biochemical substance) such as protein, or a analyzing device for such substance. Specifically, the microchip is used in the measurement that takes advantage of intermolecular interaction such as immune reaction in a clinical test or the like (measuring technology using a SPR (surface plasmon resonance), measuring technology using a QCR (quartz crystal microbalance), or measuring technology using a functional surface from a gold colloidal particle to a ultrafine particle.
The microchips can be fabricated at a relatively low cost. Thus, it is possible to prepare and use the microchips in a large quantity depending upon a required quantity in a chemical analysis. Therefore, the microchips can be treated as the disposal devices. It is possible to omit the cleaning and maintenance works after the analysis, unlike ordinary analyzing devices. The cleaning and maintenance works are often troublesome.
Various chemical operations such as mixing of solutions, reactions, isolation, separation, refining and detection can take place in the microchip. When the microchip(s) is incorporated in an analyzing device, the analyzing device detects reactions and other phenomena that take place in the microchip(s). For example, when the microchip is used as an SPR (surface plasmon resonance) sensor, the analyzing device may include a light source having a laser unit (or other light emitting element) to emit monochromatic light, and a light receiving element to receive light from the microchip. The microchip is incorporated in an analyzing device dedicated to a particular use, so as to enable a desired analysis.
On the other hand, many of conventional analyzing devices dedicated to a particular use include large and expensive laser units and/or large and expensive microscopes to carry out desired detection. To deal with such shortcoming, size reduction of the light source and the detecting system, including the detectors, is studied for the analysis-dedicated device.
For example, Patent Literature 1 discloses a detection system that is used with a microchip. The detection system uses a laser diode and an integrated type laser-induced fluorescence detecting element.
Non-Patent Literature 1 discloses the integration of OLED (organic light emitting diodes) into a microchip.
FIG. 15 of the accompanying drawings schematically illustrates an analyzing process that uses a microchip.
Firstly, as shown in FIG. 15(a), a specimen (object to be analyzed) 4 is taken out by a micropipette 2 by a necessary amount for analysis. The specimen 4 is obtained from, for example, a human body, an animal, river or wasted liquid. A pretreatment may be conducted before the specimen 4 is taken out by the micropipette 2 to remove impurities or the like, if necessary. Then, the specimen 4 is dropped into a fluid passage (flow path) of a microchip 1 from the micropipette 2 (FIG. 15(b)).
The specimen is received in the microchip 1 and a reaction of the specimen takes place (e.g., a biomolecular reaction between an antigen and an antibody) in the microchip 1. Subsequently, the microchip 1 is loaded in an analyzing device 5. The reaction of the specimen is detected by the analyzing device 5 with light emitted from a light source of the analyzing device 5. The detection results, in the form of detection signals, are processed by a control tool 5a. The control tool 5a processes and analyzes the detection signals. The control tool 5a is also used to display the analysis results, control various setting of the analyzing device 5, log-in data, and send data (FIG. 15(c)). The analysis-dedicated device includes the analyzing device 5 and the control device 5a. 